The pumping of a gaseous laser medium by nuclear reaction products to excite a population inversion is a known technique. Lasers which employ such techniques are generally referred to as direct nuclear-pumped lasers since the nuclear reaction products are used to directly ionize and excite the laser medium. Such lasers have the potential for high-power applications since existing nuclear reactors produce large neutron fluxes and the neutrons can penetrate a high-pressure gas and excite nuclear reactions uniformly throughout the gas volume. Previous direct nuclear-pumped lasers have relied on a coating of solid .sup.10 B or .sup.235 U to produce nuclear reaction products when bombarded by thermal neutrons.
The primary disadvantage of previous direct nuclear-pumped lasers is their reliance on solid coatings of fissionable material, (.sup.10 B or .sup.235 U). A substantial part of the charged particle energy is lost in traversing the .sup.10 B or .sup.235 U coatings as well as the disadvantage of all the reaction products being created at the surface of the laser tube which leads to nonuniform excitation of the laser medium at high pressures.
It has been recognized in the past that .sup.3 He in gaseous form could be used in place of solid coatings as the fissionable material. However, as far as the inventors know, no one in the past has been able to achieve lasting in a .sup.3 He minority gas mixture.
It is therefore the primary object of this invention to provide a volumetric direct nuclear pumped laser in which gaseous .sup.3 He is used as the fissionable material.
Another object of the invention is to provide a volumetric direct nuclear pumped laser in which the gaseous material is .sup.3 He mixed with a lasting gas.
Other objects and advantages of this invention will become apparent hereinafter in the specification and drawings.